1. Field of the Invention
The present invention is generally in the field of semiconductors. More particularly, the invention relates to the packaging of semiconductor dies.
2. Background Art
A power module, such as a motor drive inverter, for example a three-phase inverter, can include at least one power switch that can be, for example, an insulated-gate bipolar transistor (IGBT) or a power metal-oxide-semiconductor field-effect transistor (MOSFET). As an example, an IGBT die can placed in the power module, and a diode die can be connected in parallel with the IGBT die as a freewheeling diode. Although the dies may be capable of high performance, performance of the motor drive inverter can be limited by how the dies are connected. For example, inductivity, electromagnetic interference (EMI), and parasitics are of great concern when connecting the motor drive inverter.
The motor drive inverter power module is typically formed by wire bonding the dies to conductive traces on a substrate of the power module to connect the dies. The design and layout of the motor drive inverter can be complex as the motor drive inverter may include many dies. For example, a three-phase motor drive inverter can include three IGBT dies as high side power switches, another three IGBT dies as low side power switches, and corresponding diode dies as freewheeling diodes for each IGBT die. As such, the conductive traces must often follow long routing paths on the substrate of the power module, and can have undesirably asymmetric current paths with high inductivity. Also, it can be difficult to make the conductive traces sufficiently wide due to the long routing paths required to connect the dies. Thus, performance of the motor drive inverter can suffer. Furthermore, the motor drive inverter may have a large footprint and poor power density.
Thus, there is a need in the art for the capability to form an improved power module, such as an improved motor drive inverter, while overcoming the drawbacks and deficiencies in the art.